Aviation has different impacts on the climate. While the EU and ICAO have started to address the impacts of CO2 emissions, the other impacts remain unaddressed directly. This note argues that they should be addressed in line with established European policy as well as because of the precautionary principle. In terms of radiative forcing, the non-CO2 climate impacts of aviation are estimated to be about as large as the impacts of CO2. In other words, the cumulative effect of the non-CO2 impacts on the current climate is about as large as the cumulative effect of aviation CO2 emissions.